Combined airplane-helicopter flying machine



COIVIBINED AIRPLANE-HELICOPTER FLYING MACHINE Henrich Carl Johann Focke,Sao Joze dos Campos, Brazil, assignor to Ministerio da Aeronautica,Director do Material, Aeroporto Santos-Dumont, Rio de Janeiro, BrazilThe present invention relates to an improved combinedairplane-helicopter flying machine. Machines of this kind are knownhaving at least one propeller of which the propeller shaft is angularlymovable about an axis extending transverse to the centre line of saidshaft and transverse to the longitudinal axis of the machine, fortransforming the machine from the condition to operate as a helicopter,into the condition for rapid forward flight and vice versa. In order toprevent the wings unfavourably influencing the air flow produced by thepropeller or propellers, it has been proposed in the case of a combinedairplane-helicopter flying machine having two propellers, to rigidlymount said propellers on the respective wings, and to swing said wingstogether with the propellers mounted thereon about an axis at rightangles to the longitudinal vertical central plane of the machine, inorder to transform the machine from one position into the other. This ofcourse involves a complication of the construction of the machine.

If such complication is to be avoided the main planes will have to befixed stationary with respect to the ma chine, but in that case thepropeller, or propellers should be arranged so far in front of saidplanes, that the air flow from the propellers passes the front edge ofthe respective wings. This, however again results therein that the forceof the propeller or propellers no longer passes through the centre ofgravity of the machine but at a considerable distance therefrom so thata free moment is set up which has to be opposed by a counter moment.

According to the invention at least one additional propeller is arrangedat some distance behind the wings, such additional propeller being soconnected to the machine that it may be swung about an axis transverseto the'axis of its shaft and to thelongitudinal axis of the machine.

In the case of an embodimenthaving three propellers, according to theinvention, two of such propellers may be arranged one on either side ofthe longitudinal vertical central plane of the machine and in front ofthe wings, whilst a third propeller is arranged in said central plane onan elevator carried by two tail beams, the various distances being sochosen, that the resultant of the propeller force passes through thecentre of gravity of the machine.

In this manner however, at least when the three propellers are of equaldimension and have equal torque, it is not possible to obtain completeequalisation of all torque reactions since in that case the torquereaction of one of said propellers remains. v

For this reason, according to the invention it is proposed to arrange,either the transverse axes for the angular movement of the twopropellers in front of the wings, or the transverse axis for the angularmovement of the rear propeller, to be at an inclination with respect tothe horizontal plane.

Thus in the position of the propeller for vertical or substantiallyvertical flight, the axis of such propeller or nited States Patent "icepropellers has a small lateral inclination, and this may be so chosenthat the influence of the free torque reaction on the machine iscancelled out.

The invention will hereinafter be further described with reference tothe accompanying drawing in which:

Figure l is a diagrammatic plan view of an embodiment of a flyingmachine according to the invention, having three propellers.

Figure 2 is a perspective view of the elevator as inclined with portionsof the tail beam removed to show details of the mechanism involved.

In these figures the propellers are diagrammatically shown in full lineswhen in position for vertical flight and in dotted lines in the positionfor rapid forward flight.

Referring to Figure 1 the flying machine comprises a central fuselage 1having wings 2, from which fuselage two parallel tail beams 3 extendrearwardly, such beams being arranged one on either side of the verticallongitudinal centre plane of the fuselage. An elevator 4 is arrangedbetween said beams at the rear end thereof and swingable about an axistransverse to said longitudinal centre plane, the dotted lines showingthe position of said elevator with the machine arranged for forwardflight.

Where the tail beams 3 project forwardly beyond the wings 2, each beamcarries a propeller 5, 6 of which the shaft is adapted to be swung aboutan axis 7 and 8 respectively these being diagrammatically shown in thefigure; these axes 'i, 8 both transversely to the respective propellershaft and to the longitudinal axis of the machine in such a manner thatthe propellers, by swinging about said axes, may be adjusted from theposition for substantially vertical flight into the position for rapidforward flight and vice versa, or into any intermediate position.

The length of the forwardly projecting portions of the tail beams 3 isso chosen, that in the position of the propellers for substantiallyvertical flight the air flow produced by the propellers entirely passesbeyond the forward edge of the respective wings, and therefore is notdisturbed or does not produce increased air resistance.

It will be noted that the resultant of the lifting forces of bothpropellers 5, 6 does not pass through the centre of gravity of themachine, so that without further 'provisions the machine will turn abouta horizontal transverse axis. To take up this free moment I provide onsaid elevator 4 and in the vertical longitudinal centre plane of themachine, a third propeller 9, which is also swingable about an axistransverse to the propeller shaft and to said centre plane, saidadditional propeller being placed at a distance from the centre ofgravity of the machine such that in the condition of the machine foroperating as a helicopter, the propeller 9 produces a counteractingmoment about the transverse axis through the centre of gravit whichmoment therefore cancels out the moment of the two propellers 5 and 6.

in this embodiment with three propellers, however, if all propellers areof equal dimensions and have the same torque, there still remains thefree torque reaction of one of such propellers which causes the machineto rotate about an axis which is located in the vertical longitudinalcentre plane of the machine and is at right angles to the longitudinalaxis of the machine, because always two propellers may rotate indifferent directions and therefore compensate for their mutual torquereaction but then the torque reaction of the third propeller remains. itis necessary to compensate for this free torque reaction by an oppositetorque. Very often a special small propeller having a horizontal axisand mounted preferably at the tail of the plane is used therefor, but ifthere are more than one lifting propellers as in this case it is notnecessary to add that special small propeller for counteracting thetorque. In the case mentioned it is possible. to give one ormore of thecludes a small angle with the vertical in a plane perpendicular tothelongitudinal axis of the machine; Due to this the propeller'willinot'exert a vertical 'for eqn; the

plane but will also producea small horizontal force comv Thishorizontalforce component maybe used for counteracting the free torquereaction on theplane .above referred-to; For'this purpose theverticalaxis ponent.

of the rear propeller 9 in Fig. 1 may be somewhat inclined in a plane.perpendicular .to the longitudinal axis of the machine. Of course alsoboth axes of the forward propellers; 5,"6 could be inclinedrelative tothe vertical They must and in the same plane forthe same purpose. beinclined, however, in the same. sense.

1 I-t will be understoodthatof both propellersfiand 6 in Fig.1 only onecould take the inclined position above referred to but'then thehorizontal force .jcomponent act symmetrically'on the fuselage which'however, is

not an essential disadvantage. 7

Figure 2 illustrates the. connection between a. tail beam 3 of Fig. landthe elevator 4. This elevator is provided at'its middle with an enginecarrying the propeller 9. Theelevator 4 can be swung about thehorizontal axis '21. Theelevator 4 is shown in Figure 3 in the position7 inwhich the axis of the propeller 9 is vertical which f means that themachine is in helicopter position.

7 The shaft incorporating the axis 21 is supported in Y1 bearingscarried by the tail beams 3. The bearing is indicated by the number 22.-It is carried by thefree end' of a lever '23. The other end of thelever 23 isiro' tatably supported ona pivot 24 fixed n the tail-beam 3.'If the lever 23 is swung in the 'direch'onof the arroW25 about the"pivot 24, thebearing 22.will risefIf at the same time the correspondinglever 23. in the.,..other tail 7 V beam is swung in the' opposite.direction the bearing' at "the other end of the axis21 will be loweredand.'that means that the elevator 4 will take. an inclined position withrespectto' the horizontal plane, i; e.-, a plane perpendicular to thecentral plane of the machine and including the longitudinal axis 26 ofthe machine.

'If the elevator 4 assumes the said inclined position,=the' axis of thepropeller 9 will include an angle with the vertical direction and-thatwill enable the propeller 9 to exert a horizontalforce'counteracting thetorque about .a vertical axis resulting from the three propellers ifthey "are in the helicopter position. 7 V .j

What'I'claim is: a

fuselage .on' both sides thereof, supporting means rigidly liftingpropellers a some- I V whatinclined position which means that their'axis innecessaryfor compensation of the free torque would not 1. Acombined airplane helicopter flying. machine comprising a fuselage,wings rigidly attached to said I attached to and extending forwardofsaid wings, one on V either side of 'said fuselage, a first propellerarrangedin front of said wings on one side of the vertical longitudinalcentralplaneof the) machine, a second 'propellenar I ranged on theopposite fside'of said central plane 'symmetrically with said firstpropeller, means for mounting said first and second propellers on saidsupporting means,

so that the said propellers can be swung :about anaxis' transverse tothe longitudinal axis of the machine and perpendicular to said central"plane, two spaced parallel tail beams rigidly attached-to and rearwardlyextending. from said win a'ene on either side of said fuselage, an;

elevator extending between saidjtail beams at the rear ends thereof, anda third propellernlounted on said ele-.

vator, with its axis of rotation in said centralplane, and

means pivotally connecting saidjelevator to said'bean'is so J in thatsaid elevator together with said third propeller may be swung about anaxis transverse. to. the-longitudinal axis of the machine andperpendicular to .said" central.

plane. a

2. A combined'airplane helicopter flying'mac hine as claimed in-claim 1,withnieans; on-at least one or thesaid mountingmeans for. mounting therespectivepro i eller on its-supporting means with extra movability so.f

that the propellerin question can beswung, apart from its swinging aboutan axis transverse to the longitudinal axis of the. machine -andperpendicular to said central plane, about 'a sec'ondaxi s parallel tosaid longitudinali V axis to an angle s'ufiicient to enable thepropeller inques: i

.tion to ,counteractthe. free torque on the machineabout "-a verticalaxis remaining as a resultant of thetorques'of all propellers when.imposition for helicopter flight.

- 7 3. A combined airplane helicoptegflying machine {as- V claimed inclaim 1', with'means'for mounting said elevator for a swingingmovement.{'abont' the longitudinal axis of. l

the machine to assume an; inclined position: with, respect positionforhelicoptenflight. V

. erase Cara tile file of thi spatent '1 UNITED STATES PATENTS

